The return of strip till

Do you remember more than 10 years ago, when researchers and Extension staffers were doing all they could to make strip till a reality? Back then the practice — also widely referred to as zone till — showed a lot of promise, but there were also a lot of headaches.

The key was the challenge of incorporating dry fertilizer and tillage in the fall, then coming back the following spring to try to visually line up the planter over the berm and deliver the seed and nutrients into the prepared ground. While the people interested in this technique worked hard at it, they were never able to show an economic benefit, no matter how much it seemed like the technique should have delivered that bonus.

Since the turn of the millennium however, there have been myriad advances in agronomy, technology and knowledge. Sometimes it’s a bit dizzying to keep up. Consider that the past 14 seasons have seen the advances such as the widespread adoption of Bt hybrids, Refuge-in-a-Bag convenience, stacked trait technology, higher planting populations and densities, and full-season hybrid genetics.

Now, precision ag is helping to push the limits even further with variable-rate planting, enhanced seed singulation and a growing awareness of the full benefits of real-time kinematics (RTK) technology. The science is complex, but the basic concept is simple. RTK delivers greater positioning accuracy. It’s a complex process that takes a GPS signal, interprets the wave carrying that signal and refines a location to within a fraction of a centimetre, and it’s this GPS accuracy that can deliver agriculture inputs exactly where they need to go.

Thanks to the latest enhancements with RTK, strip till is making a comeback, primarily in the northern tier states such as Minnesota and Wisconsin. In that region, the practice is finding favor with growers on lighter soils and marginal ground who are looking to do less tillage but also want better fertilizer placement. Although it can be accomplished successfully on loamy or heavier soils, the window for such a fall practice is more limited both by weather and harvest conditions. If growers miss that fall application opportunity, chances are they’ll just default to conventional methods in the spring.

Now, despite the differences in weather, harvest timing and management practices, the strip till trend is also making its way back into Eastern Canada. Agronomists, advisers, dealers and extension personnel are monitoring its uptake, as well as the opportunities to make the most of the trend. Tony Balkwill of Nithfield Advanced Agronomy, has seen an increase in grower interest in strip till in the past five years, and he believes more growers will be adopting it in years to come.

In Balkwill’s experience, it’s a matter of showing the farmer — by way of a good soil sampling — where the highs and lows are, and instead of applying something on a “straight rate” basis, trying more of a prescription application with the strip till. It’s the same amount of fertilizer, Balkwill says, it’s just being moved to those spots in the field where it’s going to be the greatest benefit, and the application method is incorporated with minimum tillage. Once farmers see the difference that such precision makes, they seldom go back.

“You get some innovative guys doing it, and good farmers pick it up, then a neighbour, and away you go,” says Balkwill, who cites two primary factors for its increasing interest. “We have great equipment options with planters, to be flexible in conventional, mid-till and no-till situations, all on one rig. So if we fall strip till, we assume there’s a slight no-till situation. If we come in the spring, because a lot of those rows may have some trash on them or have firmed up a little bit, you need to address that so you don’t get hair-pinning. So guys can slow down with the planter, make sure they have a good seed depth and a good bed so that they’re not just punching a bunch of cornstalks down into the trench. There’s been a lot more availability of just add-ons to make a planter into whatever you want.”

In the U.S., the recent uptake has come primarily because growers are looking for opportunities to accomplish more with a single pass. Fall strip till is more prevalent in the Midwest, particularly with the popularity of getting on fall anhydrous, and Balkwill says he knows of a number of custom dealers in the U.S. who are now offering strip-till services to help ease the bottleneck that can come later in the season.

On this side of the border

In Ontario and across Eastern Canada, the return of strip till has been somewhat slower. But the arrival of RTK technology has been arguably the biggest factor in grower interest, on either side of the border. Still, there are several “cultural” differences between strip-till practices here and those in the U.S., and according to Greg Stewart, OMAF’s corn industry lead, the biggest factor is the preference for fall nitrogen applications in the U.S.

“Don’t forget the fall nitrogen factor that still plays on what’s perceived as strip till,” says Stewart, referring to growers in the Midwest. “It’s based on the idea that they’re going to go out and put down fall anhydrous anyway, so they’re thinking, ‘Let’s make it into a strip-till operation while we’re putting fall anhydrous out.’ Here (in Ontario), we don’t have that springboard to come from, which has always been a big driver of the fall strip-tillage phenomenon in certain areas.”

In the U.S., integrating fertilizer and strip till almost always translates into the combination of fall nitrogen along with the tillage practice, Stewart explains. In Ontario, it means bringing dry products and integrating dry fertilizer (particularly phosphorus and potash) into the strip. That can be done in the fall, but Stewart’s personal preference is to apply them in the spring.

“If you thought you needed to do a fall pass, well maybe you were going to do that anyway,” explains Stewart. “But then, heaven forbid, if you need to touch up that strip in the spring again, well now you’re at two passes. And then what happens if you realize that you used to just broadcast all of your fertilizer before, and you can’t do that now, particularly with nitrogen, so you’re going to have to move from broadcast nitrogen to side dress nitrogen. So where are the savings in this strip-till system (with three passes)?”

Stewart adds that there’s interest from those growers who wanted to be doing some form of conservation tillage, but didn’t like the idea of working in no till, and the use of RTK certainly continues to feed into that notion.

“And I personally believe there’s more appetite for trying to make the fertilizer-strip-till combo work,” says Stewart. “We have an increasing amount of gear that could bring that together, so that would be another component — that desire to try to amalgamate the fertilizer and strip till.”

Worth more research

Both Balkwill and Stewart are looking at research projects coming in the spring. In November 2013, Stewart received approval on a two-year study that will tackle the idea of new designs on strip-till equipment, with an eye on improving or streamlining operations in the spring, including the use of fertilizer blends and in particular, poly-coated urea.

“That’s so the risk of burning the seed with just straight urea can be eliminated, and then after that we can test the GPS for the contour ability, and that’d be a system we’d really like to sink our teeth into,” Stewart says. It’s a lot to consider — spring strip till with one pass, plus fertilization in one pass, and even do it all on the contours and then be able to plant. Then there’s the variety of options in terms of equipment, including fall versus spring, applying fertilizer in the fall versus applying it in the spring. “But this is a targeted approach that digs into making it a system that is spring only, all fertilizer only and GPS driven, to see if we can’t put a package together that gets more people looking at it.”

With Balkwill’s project, he’s hoping the spring of 2014 will bring an opportunity to test strip till on soybeans. It’s well accepted that strip till is regarded as more of a corn-planting technique, but Balkwill believes stripped soybeans may work too.

“We’re going to be stripping our 30-inch beans to see what kind of response we’ll get,” Balkwill says. “They start with a bunch of variable-rate seeds with soybeans, and we’re actually dropping the populations down to (a range between) 100,000 to 190,000 in one field, and we’ll put in low populations in rich soil, and we limit moulds and growth, and we’ll get dry-down with a bit more even maturity.”

Balkwill adds that the yields have been consistent and the economics have been better, so some farmers are considering dropping their seeding costs a little bit. He’s eager to see how the crop responds to all of these management parameters with the strip-till layer under the soil surface. Soybean roots, he says, are more passive, which means they don’t go down into the soil very deep, and to get the added penetration and moisture conservation and nutrient setup that comes with a strip-till regimen is something he believes is worth testing. And he thinks strip-till soybeans will become something that more growers try to incorporate into their operations.

If there’s a hurdle to overcome with strip tilling soybeans, it’ll be the setup into 30-inch corn rows. Balkwill says that some growers are looking at running 15s on either side of 30-inch corn rows. Or some that run 30-inch corn and 20-inch soybeans may just move their soybean rows two inches either side.